Apparatus for protecting well pipe



March 25, 1969 A. o. TIMMONS 3,434,191

APPARATUS FOR PROTECTING WELL PIPE Original Filed Aug. 27. 1965 Sheet 51" 2 A. 3, 7/f77fi70/7J INVENTOR.

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APPARATUS FOR PROTECTING WELL PIPE Original Filed Aug. 27. 1965 Sheet 2 of 2 INVENTOR.

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United States Patent 3,434,191 APPARATUS FOR PROTECTING WELL PIPE Arch e Durwood Timmons, Morgan City, La., assignor to Tri-State Oil Tool Industries, Inc., Bossier City, La., a corporation of Delaware Original application Aug. 27, 1965, Ser. No. 483,194. Divided and this application Mar. 12, 1968, Ser. No. 712,439

Int. Cl. B233) 19/00, 19/04; E21b 33/03 US. Cl. 29-200 7 Claims ABSTRACT OF THE DISCLOSURE Apparatus for protecting a well pipe having a plurality of force transmitting elements adapted to engage a pipe at a sufiicient number of points to uniformly transmit force to the pipe without damaging the pipe. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

This application is a divisional application of my prior copen ding application, Ser. No. 483,194, filed Aug. 27, 1965".

Summary The present invention relates to a method of protecting well pipe while it is being run in and removed from a well bore. More particularly, the invention relates to a protective device which is interposed between the well pipe and the usual tongs to prevent damage to said pipe which may be caused by direct engagement of said tongs with the pipe surface.

As is well-known, the usual well pipe tongs include tong dies, usually three in number, which grip the exterior of the pipe. =By reason of the relatively large spacing between the dies, it often occurs that excessive pressure is applied to the pipe at the spaced points of contact which results in ldeforrning the pipe from its truly round shape; in some instances, the surface of the pipe is actually flattened in the area of contact with the gripping die.

It is, therefore, one object of this invention to provide an improved method and means for protecting the pipe, wherein the area of gripping contact with the surface of the pipe is greatly increased as compared to the usual three point contact of the usual tongs, whereby possibility of damage to the pipe during the usual handling thereof is obviated.

An important object of the present invention is to provide a protective bushing or force-transmitting unit which is engageable around a well pipe and which has amplified gripping contact with said pipe so that it engages the pipe in substantially the full circumference thereof; the exterior of the bushing being engageable by the usual pipe tongs so that torque may be applied to the pipe through the bushing without danger of damaging said pipe.

Still another object of the present invention is to provide a readily removable protective bushing for a well pipe adapted to be interposed between the well pipe and the ordinary well-known tongs; said bushing having gripping elements arranged substantially throughout the major area of its bore to distribute torque forces uniformly around the circumference of the pipe; said bushing having sufficient wall strength so that the usual three point contact of the tongs with its surface will not flatten or otherwise deform said bushing.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:

FIGURE 1 is a schematic illustration of a section of well pipe which extends into a well bore and which is supported in the usual manner at the sun-face of the well.

FIGURE 2 is a similar view showing the installation of the protective device, constructed in accordance with the invention, upon the well pipe.

FIGURE 3 is another similar view showing the engagement of the protective device by the usual pipe tongs, FIGURES 1 through 3 illustrating the handling of the well pipe in accordance with the method of the present invention.

FIGURE 4 is an enlarged view, partly in elevation and partly in section, of the protective device applied to the well pipe.

FIGURE 5 is a horizontal cross-sectional view, taken on the line 5-5 of FIGURE 4.

FIGURE 6 is a schematic view taken along line 6-6 in FIGURE 3 and illustrating the manner in which the protective device is interposed between the pipe and tongs.

Description of the preferred embodiments The running and pulling of well pipe strings from a well bore require considerable handling of the well pipe at the surface. A part of this handling, and particularly the initial torque to break or start unthreading of one section of pipe from another and the final torque to make up or complete the threading of one section of pipe into another, is generally handled by a large wrench called tongs. The usual tongs are provided with a plurality of pivotable jaws in which are mounted tong ties with pipe-gripping teeth on their interior surface. The tongs are adapted to engage around a well pipe with the gripping teeth of the dies in engagement with the outer surface of the well pipe. Because of the particular construction which makes the tongs readily engageable with and removable from the pipe, the number of dies which may be used is limited and generally three dies are provided. This gives a three point contact or engagement with the pipe with the three gripping points spaced a substantial distance from each other.

When the tongs are applied and rotated to rotate the pipe, the relatively wide spacing between gripping points often results in damage to the pipe. Such damage may be a deforming of the pipe by flattening the areas in contact with the gripping dies or the outer surface of the pipe may be scarred or galled if there is any slippage of the gripping dies. The disadvantages stem from the fact that the dies are so widely separated that a uniform circumferential gripping is not obtained.

The present invention therefore provides a method and force-transmitting unit for the handling of well pipe with tongs in which the rotation of the tongs is efliciently transmitted to the Well pipe without danger of damaging the well pipe. The improved results are accomplished by uniformly distributing the gripping engagement with the pipe substantially throughout the circumferential area of the pipe.

Referring to FIGURE 1, a well pipe string consisting of sections, two of which are illustrated at A and B, extends within a Well bore W. The string is supported by the usual supporting slips S which are mounted in the tubing head D at the well surface. The pipe may be either being run in or removed from the well bore. As is well-known, the string is made up of pipe sections con nected by couplings C.

In carrying out the present invention, a protective bushing or force-transmitting unit P is clamped around the well pipe section B at a point above the coupling C and, as will be explained, said bushing grips the pipe at a plurality of areas around the pipe surface to distribute the gripping engagement about said pipe surface. Thereafter, the tongs T, supported by the usual cables L, are engaged with the protective bushing P whereby rotation of the tongs is transmitted through the bushing to the pipe to torque the pipe and break out the threaded connection between the pipe section B and coupling C. Once the unthreading is started, any suitable method to complete the unthreading of the connection may be used although it may be desirable to use the tongs and bushing for this purpose. The tongs T are then removed from engagement with the protective bushing P, the bushing P is removed from around the well pipe section B and the section A raised to a level above the bowl D. The same method of disconnecting will be used to unthread such section A from its lower coupling.

The method of handling and providing a protected engagement of the pipe sections by the tongs T will be the same for the running of a string of well pipe into a well bore, the protective bushing first being applied to the well pipe and then being engaged by the tongs so that the well pipe is protected from damage without sacrificing the needed torque-transmitting engagement between the tongs and the well pipe. The protective bushing of the present invention provides this needed engagement between the well pipe and the tongs for make-up or breaking torque which is to be applied to the well pipe by the tongs while protecting the well pipe from damage such as that often caused by the engagement of the limited number of tong dies with the surface of the well pipe.

A protective bushing embodying the features of the present invention is illustrated in detail in FIGURES 4 and 5. This protective bushing is shown in engagement with a well pipe 11. The protective bushing 10 includes two members 12 and 13 which are each substantially semi-cylindrical. They are joined along one edge by a hinge structure 14 and at the other edge when closed in clamping engagement with Well pipe 11 as shown by the releasable latch mechanism 15. The interior of the members 12 and 13 includes gripping means, such as the illustrated plurality of rows of pipe-gripping teeth 16, which will engage the well pipe 11 at a multiplicity of points, such points of tooth engagement being substantially greater in number than the number of points of tooth engagement between the same pipe 11 and the usual tongs. By providing the increased number of gripping points with the pipe, the force applied to the pipe when the bushing is rotated is uniformly distributed circumferentially around the exterior of the well pipe to obviate deformation of said pipe. The drawings illustrate the teeth being formed integral with and on the interior of the two members 12 and 13 but may readily be made in a form similar to tong die inserts and inserted in suitable slots in the members 12 and 13. The handles 17 and 18 are secured to the members 12 and 13, respectively.

The hinge 14 may be of any suitable design and, as shown by dashed lines in FIGURE 4, includes alternating and interengaging lugs on each of the members 12 and 13 which are connected by the hinge pin 19. It should be particularly noted that the hinge structure does not inany way extend outwardly beyond a circle defined by the outer surface of the members 12 and 13 and therefore will not interfere with the engagement of the bushing 10 by the tongs.

The latch mechanism includes the projection 20 secured to the upper portion of the member 13 at a point adjacent its open edge, the spring loaded block 21, the links 22, the latch arm 23 and the lug 24 which extends from the upper portion of the member 12 as shown. The block 21 is positioned on one side of the projection 20 and is threadedly engaged by the bolt 25 which extends through a hole in the projection 20, such hole being sufiiciently large to allow longitudinal movement of the shank of the bolt 25 therein. The spring 26 is positioned around the shank of the bolt 25 between the projection 20 and the underside of the head of the bolt 25 to urge the bolt 25 and the block 21 in a direction toward the right as viewed in FIGURE 4. The two links are pivotally secured to the block 21 by the screws 27 and 28 and are secured to the latch arm 23 by the screw 29. Latch arm 23 is secured by screw 29 to be able to pivot thereon for engagement and disengagement with the lug 24.

The operation of the latch mechanism 15 is relatively simple and quick to allow quick and easy securing of the protective bushing 10 on the well pipe 11 and also its quick and easy removal therefrom. The two members 12 and 13 are first placed around the pipe 11. Thereafter, the short end of the latch arm 23 is placed in engagement with the concave side of the lug 24, and the latch arm 23 is rotated clockwise as seen in FIGURE 5 to secure the latch mechanism. The links 22 will have a length which is short enough to cause the block 21 to move away from the projection 20 during latching to compress the spring 26. When the latch arm 23 has moved against the side of member 12 as shown, the latch will be past center and the force provided by the compression of spring 26 will assist in maintaining the latch mechanism 15 in its closed position. Thereafter, the protective bushing 10 will be ready to receive the tongs on its exterior surface below the latch mechanism 15. Also, this force of spring 26 will hold the teeth 16 against the outer surface of pipe 11 thereby clamping the bushing 10 on the pipe 11.

From FIGURE 5 it can clearly be seen that the engagement of the rows of gripping teeth 16 with the well pipe 11 will be at eight different locations around the circumference of the pipe. A similar pipe would be engaged directly by a set of tongs at only three different locations, each location being comparable only to one of the eight locations illustrated. This greater multiplicity of gripping engagements with the exterior of the well pipe will equally distribute the applied force circumferentially around the pipe surface to thereby protect the well pipe from damage such as crushing and surface galling. The protective bushing has its wall of sufficient thickness to resist any deformation by the three point contact or gripping engagement of the tongs. Thus, the usual tongs will not damage or deform the bushing which is interposed between said tongs and the pipe. The bushing provides a simple and effective means for distributing the torque forces, which are applied to the well pipe, uniformly around the entire circumference of said pipe.

What is claimed is: 1. A protective force-transmitting bushing comprising, a pair of substantially semi-cylindrical members, said members being secured together along one side by a hinge connection and releasably connected at the other side by a latch mechanism, said latch mechanism being positioned near one end of said members and said hinge connection positioned within the confines of the outer surface of said members to thereby provide an uninterrupted exterior surface suitable for engagement by tongs, and a plurality of gripping elements on the interior of each of said members for pipe-gripping engagement with a pipe, said elements engaging the pipe substantially throughout the circumference of said pipe to distribute torque forces applied to the exterior of said bushing uniformly throughout the circumference of said pipe. 2. A protective force-transmitting bushing as set forth in claim 1 wherein,

the gripping elements are gripping teeth formed integral within the inner surface of the semi-cylindrical members. 3. A protective force-transmitting bushing according to claim 1 wherein,

said gripping elements comprise gripping dies removably mounted in the semi-cylindrical members.

4. A protective force-transmitting bushing as set forth in claim 1 wherein,

said latch mechanism is spring loaded to maintain said bushing in tight clamping engagement with the pipe on which it is installed.

5. A protective force-transmitting bushing as set forth in claim 1 wherein,

each semi-cylindrical member of said bushing has a wall of suflicient thickness and strength to prevent its deformation when engaged by pipe tongs.

6. In combination with a well pipe and pipe tongs, a

protective force-transmitting unit comprising,

a pair of substantially semi-cylindrical members which are hinged to facilitate engagement of the members about the well pipe,

means for latching said members in position on said pipe, and

means on the inner surfaces of said members providing amplified gripping areas engaging the pipe substantive forces to the pipe,

said bushing being adapted to be engaged by said pipe tongs which impart rotation thereto,

the interior gripping area of said members with the pipe being substantially greater than the gripping area between the tongs and the exterior of the members.

'7. The combination set forth in claim 6 wherein,

the means on said members which provides amplified gripping areas comprising a plurality of gripping teeth which extend over the major area of the circumference of the well pipe.

References Cited UNITED STATES PATENTS 1,197,790 9/1916 Chapman 16677.5 5 2,322,918 6/1943 Brooke 29--240 3,239,016 3/1966 Alexander 173-164 THOMAS H. EAGER, Primary Examiner.

US. Cl. X.R. 

